From 595ef8b10ad81c6033df53dfbfdb8c1b01f6de87 Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@nicira.com>
Date: Fri, 25 Apr 2014 13:50:48 -0700
Subject: [PATCH] ovs-thread: Quiesce in xpthread_barrier_wait().

Otherwise the udpif revalidator threads can postpone RCU callbacks
essentially forever, especially if there are many revalidator threads and
little network traffic.

Reported-by: Alex Wang <alexw@nicira.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Alex Wang <alexw@nicira.com>
---
 lib/ovs-thread.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/ovs-thread.c b/lib/ovs-thread.c
index 3ca686f35..f33f5f110 100644
--- a/lib/ovs-thread.c
+++ b/lib/ovs-thread.c
@@ -240,7 +240,10 @@ xpthread_barrier_wait(pthread_barrier_t *barrier)
 {
     int error;
 
+    ovsrcu_quiesce_start();
     error = pthread_barrier_wait(barrier);
+    ovsrcu_quiesce_end();
+
     if (error && OVS_UNLIKELY(error != PTHREAD_BARRIER_SERIAL_THREAD)) {
         ovs_abort(error, "pthread_barrier_wait failed");
     }
-- 
2.43.0